Evaluation of the new antimicrobial benziothiazolinone for management of fire blight disease of pear.

Background: Fire blight, caused by Erwinia amylovora, is a devastating disease that affects apples and pears, leading to significant economic losses worldwide. The disease is typically managed through a combination of biological, cultural, and chemical strategies. Due to the emergence of antibiotic resistance and concerns regarding chemical residues, there is an urgent need for new bactericides that are both highly effective and low in toxicity. Recently, the Ministry of Agriculture and Rural Affairs of China approved the registration of a new bactericide, benziothiazolinone also known as 1,2-Benzisothiazol-3-one.

Results: The assessment of benziothiazolinone demonstrated an EC₅₀ value of 0.48 µg/mL against E. amylovora BZ16 after a 10-hour inoculation period, and 0.67 µg/mL after 16 h. Furthermore, benziothiazolinone displays a broad antimicrobial spectrum against various microorganisms, including bacteria, fungi, and oomycetes, as evidenced by its EC₅₀ values. Prolonged exposure to benziothiazolinone was found to enhance the production of amylovoran in the E. amylovora strain BZ16^BITR; however, this treatment significantly diminished the pathogenicity of the strain. Resistance risk analysis indicates that E. amylovora has a low risk of developing resistance to benziothiazolinone. Results from two-year field trials demonstrated that benziothiazolinone could significantly reduce the disease incidence of fire blight. Compared to the streptomycin control, the application of benziothiazolinone exhibited excellent efficacy, achieving over 80% effectiveness against the disease.

Conclusion: These findings indicate that benziothiazolinone is a promising agrochemical for the management of fire blight of pear.